murray



-3 Sheets-Sheet 1.

.(No Model.)

A. B. MURRAY. ATMO$PHERIG BRAKE.

-No. 369,805. PatentedSept. 13, 1887.

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Witnesses:

N. PETERS. mwmulho hnr. wzshin wn. D. c.

(N0 Mxlel.) 3 Sheets-Sheet 2.

A. B. MURRAY.

ATMOSPHERIC BRAKE.

No. 369,805. Patented Sept. 13, 1887.

Witnesges:

(No Model.) 3 Sheets-Sheet 3. A. B. MURRAY. ATMOSPHERIG BRAKE. No.369,805.. Patented. Sept. 13, 1887.

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a o f Witnesses;

iUNITED STATES PATENT @rrrcn.

I ARCHIBALD B. MURRAY, OF SAN RAFAEL, CALIFORNIA.

ATMOSPHERlC BRAKE.

SPECIFICATION forming part of Letters Patent No. 369,805, datedSeptember 13, 1887.

' Application filed September 1, 1886. Serial No. 212,433. (No model.)

To all whom it may concern.-

Be it known that I, ARGHIBALD B. MUR- RAY, a citizen of the UnitedStates, residing at San Rafael, in the county of Marin and State ofCalifornia, have invented certain new and useful Improvements inAtmospheric Brakes, of which the following is a specification, referencebeing had to the accompanying drawings, in three sheets.

My invention relates to that class of steampower air-brakes known asautomatic or safety brakes, and in which an air-coinpressor compressesair to the desired density into a main reservoir on the locomotive orcar, and an auxiliary reservoir and brake-cylinder and interposed valvedevice are employed on each car, with pipe-connections from one to theother; and my invention consists in the employment of an air compressorand reservoir, an auxiliary reservoir, a brake-cylinder, two lines oftrain-pipe, a straight air-valve attached to the reservoir to preventthe backward escape of air from the reservoir, an automatic valve forcontrolling air from the receiver to the brake-cylinder, an engineersquadruple valve provided with a spring-retaining piston in the lower endof the shell or case thereof as an escape-valve, and two airpressuregages, one of which indicates the straight air-pressure and the othershows the automatic operating-pressu re, and to the other details ofconstruction and operation, whereby the straight air and automaticbrakes are combined.

The nature of these improvements and the manner in which I proceed toconstruct, combins, and apply and use the same to accomplish the desiredend and object are fully set forth and explained in the followingdescription, the said drawings being referred to by figures and letters.

Figure l is a view in elevation of the brakeoperating mechanism asattached to a locomotive and tender. Fig. 2 is a plan view, partly insection, of my atmospheric brake mechanism. (Air'pumpnotshown) Fig.8is aview in elevation of the quadruple valve. Fig. 4 is a crosssection ofthe quadruple valve through ports or air-passages. Fig. 5 is a verticaltransverse section of quadruple valve through line 00 00, Fig. 4,showing a pipe connecting with air-release opening.

Fig. 6 is a top view of cap of quadruple valve. Fig. 7 is a horizontalsection of air-retaining valve of airreservoir. Fig. 8 is across-section through the same. Fig. 9 represents in section andelevation the automatic valve-operating mechanism connecting with thebrake-valve and cylinder. Fig. 10 is a transverse section through theports of the automatic supplyvalve.

A represents an air-pump of suitable construction, whichis secured uponthelocomotive, and is arranged to be operated by steam from the boilerina suitable manner and by suitable mechanism. (Not herein shown ordescribed.) From the pump A leads a pipe, I, which enters the reservoirB and conveys air to said reservoir.

Within thelocomotivecab is situated a quadruple operating-valve, O, withwhich is connected a pipe, 2, that extends between said valve and thereservoir B. Ata suitable point in the length of the pipe 2 a branchpipe, 3, passes therefrom and leads downward into an auxiliaryreservoir, to be hereinafter fully described. The pipe 3, I denominatethe straight air-pipe. From the valve G there extends a pipe, 4, which Icall the automatic air-pipe, and whose function it is to supply air foroperating the automatic mochanism of the brake.

. The quadruple valve 0 is provided with a supply-port, (L, where thepipe 2 enters the valve-casing, and with a release-port, a and abrake-port, a", where the pipe 4: enters the valve-casing. These portsare simply openings made in the valve-casing, and corresponding withthem are openings or passages made in the valve-plug located within saidcasing. The location and arrangement of this plug are best shown inFigs. 4 and 5. The lower end of the plug is made hollow, and contains aspring escape-valve, a, which is operative in connection with the aircoming through a port, a in the plug, which communicates at the propertime, through the port a, with the automatic air-pipe 4. The port a islonger than the ports a and M, although it is covered, excepting wherethe pipe 4. enters it, as shown in Fig. 5, and the port a is situated inthe plug below the openings that correspond with the ports and out ofline with either of them; hence when the plug is rotated the opening ICOa. will at one time be opposite the port a and at another time anotheropening will be opposite said port, the handle of the valve-plug beingproperly adjusted to cause these open-. ings to come into the propercoincidence. At one time, therefore, the pipe 4 will bein communicationwith the air-supply, and at another time the air-supply will be cut offand the pipe 4 will be in communication with the port a. When the port ais closed as respects pipe 4, the air-supply will be shut off fromentering the pipe 4, the port a will be brought into coincidence withthe port a, and there being no further pressure from the air-supply uponthe air in pipe 4 this air will expand into port a and depress thepiston a or remove it from its seat, so as to permit the excess of airto escape into the atmosphere through suitable holes drilled in thelower portion of the cap, as shown in Fig. 5. The cap,which is screwedinto the lower end of the valve-plug, and which carries the piston-stemand spring of this spring escape-valve,is simply a screw-cap, arrangedso that the spring may be compressed to any desired degree of resiliencyby adjusting the cap-piece. (See Fig. 5.)

The automatic air-pipe 4 connects with a cylinder, D, by means of asuitable branch pipe, as shown in Fig. 2, said branch pipe beingarranged to admit air to the end of the cylinder. Within the cylinder islocated an automatic device arranged as follows: Into the end ofcylinder D, opposite to where the above-mentioned air-pipe enters, isscrewed the cap b, through which passes a rod that carries a piston, andaround which rod is coiled aspring which can be depressed to any degreeof resiliency by adjusting the cappiece 1). Within the cylinder isformed an annular flange or stop, 0, which prevents the piston frompassing beyond a certain point.

The piston-rod within the cylinder D conmeets with a valve, D throughthe medium of a crank-arm, d, and jointed arm (1*. A portion of the plugwithin the casing of this valve D is cut away, as shown in cross-sectionat Fig. 10, and the casing itself is provided with three ports, 6 e 0'.The pipe f enters the casing at the port 0, and connects valve D withthe reservoir E, while a pipe, 9, enters the valve-casing at'the port eand connects said casing with the brake-cylinder H. The port 6 serves asan escape-port.

Into the outer wall of the reservoir E is screwed a valve, F, in theposition shown in Fig. 2, and constructed, as illustrated in Figs. 7 and8, with a piston, IV, a stem therefor, and a spring surrounding thestem. The stem is guided in its movements by asleeve on the screw-cap h,which cap is perforated at h if, to permit the air to pass through. Thevalve F is located between the pipe 3 and the reservoir E, and when the'air in the pipe 3 attains a suflicient pressure the piston h will bedriven inward and the-air will pass into the reservoir E through thedrilled holes h h. Upon the cap of the quadruple valve 0, above andrelieves the brakes.

described, is formed a curved stop or lug, G, (see Figs. 3 and 5,)against the ends of which the operating lever or crank G strikes in itsmovements, which are thereby limited in either direction, so as tosecure an accurate adjustment of the plug within said valve 0..

Suitable pressure-gages, I and I are provided upon the straight air-pipe3 and the automatic air-pipe 4.

Upon a short connecting-pipe, between the pipe'3 and the reservoir E, isa shut-off cock, J, which is usually to be kept closed, and,when thetrain has become disconnected or broken in two, by coupling the two hoseof the separated cars and opening this cock J the pressure from thereservoirEwillreleasethebrakes of all cars that are detached from theengine, for the air will thus be driven through the pipe 3, thehose-couplings, and the pipe 4 to the automatic-valve cylinder D, thusopening the port e and escape-port e of the valve D and thus releasingthe brakes.

In operating my improved atmospheric brake I preferably provide shut offcocks upon the hose-couplings of each car, said couplings on the rearcar being kept connected, and should these cocks on the rear car becomeopened by mistake or design the compressed air would pass from one'pipeto the other-i. 6., from pipe 3 to pipe 4and into the automatic valve,in which condition of things the brakes could not be set withoutallowing the air to escape from main reservoir. To guard against thiscontingency, I employ a cock, K, which is located in the pipe 2 Withineasy reach-of the engineer in the cab. Ordinarily this cock is keptopen; but in case the cooks in the rear end of the train's'hould becomedisarranged, as above explained, the engineer will close the cock K,which will shut off the air-supply from the reservoir B, thus allowingthe air to be discharged from the straight airpipe and the automaticair-pipe, whereupon the automatic valve D will be actuated and thebrakes will be set, notwithstanding the fact that the cocks are open atthe rear end of the train.

The quadruple valve 0 is operated by a suitable handle, as G, and whenthe brakes are off or released the said valve will bein the positionshown in Fig. 4, the ports a and (6 b8- ing closed and the ports a and aopen and the piston of the cylinder D down the full distance, thusforcing the connecting arm and valve D backward its full stroke, so asto open the ports e and c and close port 6 of valve D,

which results in releasing the pressure from the brake-cylinder H, andat the same time shuts off the pressure from the reservoir E In order toset the brakes, the lever or crank Gr of the valve is moved around untilit comes in contact with the stop G. By this means the position of theplug in said valve is so changed that the ports a and a will be openedand the ports a and a will be closed, thus simultaneously shutting offthe air-supply from the reservoir B and releasing the pressure in theautomatic air-pipe 4 and cylinder D, so that the reaction of the springin the cylinder D will move the piston of said cylinder, thus actuatingthe valve D so as to cause the ports 6 and e to be opened and the port 6to be closed. In this manner the compressed air will be allowed to passfrom the reservoir E to the brake-cylinder H, where it will act on thecontained piston and cause the brakes to be set.

It is evident that the amount of air which is to be admitted at any onetime to the cylinder H for the purpose of setting the brakes may beregulated by the movement of the handle G*, which operates the valvehence the engineer has the brakes completely under his control at alltimes. When the brakes are to be released, the handle Gr will be movedin the opposite direction to what it was before, so that the ports a anda will be closed and the ports a and a will be opened.

The relief-valve a" in the bottom of the casv ing of the valve 0, whichis constructed and arranged in the manner already described, may be setat any desired pressure which in practiceis found to be mostconvenient-at five to seven pounds, more or less.

Should the pressure be too great in the cylinder D, or of such force andin such a direction as to tend to release the air in the brake-cylinderH, the piston in this cylinder may be easily moved slightly by simplymoving the lever Gr quickly from one end of its movement to the other,or from end to end of the stop G, so that the ports a and a will bemoment-arily opened. In this way enough air will be admitted to cylinderD to force its piston downward about halfway in the cylinder, or in adirection opposite to that in which the pressure may be, thuscounterbalancing such pressure, and that movement will also close ports6 and e of valve D and prevent any of the air contained in thebrake-cylinder H from escaping. If in making this movement too much airshould pass into the cy1inder D, the relief-valve a will allow theexcess to escape through porta" and the piston in cylinder D will fallback to its central position, which movement closes ports e and e ofvalve D Having thus described my invention, what the automatic air-pipe4, the pipe 2, and

the mechanism for setting the brakes, all arranged and operatedsubstantially as shown and described.

2. The combination of the reservoir B,valve 0, having ports a, a and a,and containing a plug having a relief'valve, a and a port, a, theair-supply pipe 2, the straight air-pipe 3, the automatic air-pipe 4,the cylinder D, the valve D reservoir E, and brake-cylinder H, allarranged, connected, and operated as set forth.

3. The combination, with the air-reservoir, con necting-pipes,andoperating-valve O,of the cylinder D, containing a piston whose rodpasses through cap I) in the end of said cylinder, and around which rodis coiled a spring, the valve D connecting with said piston-rod by acrank-arm, d, and join-ted arm (1*, and constructed as specified, thereservoir E, and brake-cylinder H, all constructed and arrangedsubstantially as described.

4. In combination with the straight airpipe 3 and automaticpressure-pipe 4, the combined engineers brake-valve O, which consists ofports a a a relief-valve a with its screw-plug or piston-guide anddrillediholes, and relief-valve operating port a'ficonstructed,arranged, and operating in the manner and for the purpose herein setforth and specified.

5. The combination of an air-pump, reservoir, operating-valve,supply-pipe 2, straight air-pipe 3, automatic air-pipe 4, cylinder D,valve D having ports 6 e 6 reservoir E,

connecting With valve D by pipef entering it at e, and brake-cylinder H,connecting with valve D by pipe 9 entering it at 6*, all substantiallyas described.

In testimony that I claim the foregoing I have hereunto set my hand andseal.

ARCHIBALD B. MURRAY. [L. s]

Witnesses:

C. W. M. SMITH, CHAS. E. KELLY.

